Microphones are ubiquitous on many devices used by individuals, including computers, tablets, smart phones, and many other consumer devices. Generally speaking, a microphone is an electroacoustic transducer that produces an electrical signal in response to deflection of a portion (e.g., a membrane or other structure) of a microphone caused by sound incident upon the microphone. For example, a microphone may be implemented as a MEMS transducer. A MEMS transducer may include a diaphragm or membrane having an electrical capacitance to a reference plane or backplate, such that a change in acoustic pressure applied to the MEMS transducer causes a deflection or other movement of the membrane, and thus causes a change in the electrical capacitance. Such electrical capacitance or the change thereof may be sensed by a sensing circuit and processed.
Existing MEMS microphone implementations are susceptible to a variety of electronic noise sources that may negatively affect a signal-to-noise ratio of a MEMS microphone. Among such noise sources are flicker noise (also known as 1/f noise) and noise bias resistors used in the biasing topology of existing approaches. Also, as with any audio system, it may be desirable to improve dynamic range of MEMS microphone implementations compared to that of existing implementations.